An estimated 10 million Mexicans in the US - dual citizens, visa holders, and undocumented workers alike - will finally have a political voice back home. This week, Mexico's Congress allowed nationals living abroad to vote in elections by absentee ballot. Previously, Mexicans overseas could vote only if they came home to cast their ballots in person - a trip many found expensive or, in the case of those residing in the US illegally, too risky to make.

On Tuesday, however, Congress voted 455 to 6 to set up the mechanisms and rules for absentee balloting. President Vicente Fox is expected to sign the bill into law this week, allowing it to take effect just in time for the July 2006 presidential election.

Registered voters will have until Jan. 15, 2006, to solicit ballots by sending a letter to the Federal Electoral Institute (IFE)with a copy of their voter registry card, their address abroad, and signature. Those found eligible will be sent ballots to their addresses in the US before May 15, 2006, and any ballot received back at IFE up to 48 hours before Election Day - July 2 - will be counted. The cost of the project: an estimated 1.36 billion pesos, or $126.3 million.

"Twenty years ago they called us 'gringos' and said, 'You left, so don't meddle,'" Jorge Mújica Murias, a dual citizen who grew up in Mexico City and has been living in Chicago for 17 years, told the Monitor by phone. "Now, they are finally beginning to give us what we deserve."

Hailed and criticized

The bill was hailed by migrant activists in the US as a sign of a maturing democracy in Mexico, and of the growing recognition of the importance of this long-dismissed community, who send more than $15 billion back to Mexico each year in remittances.

Mr. Fox, in a statement, called the law a "historic deed," and his foreign secretary, Luís Ernesto Derbez, speaking to the press, said that the newly enfranchised voters would "make the fundamental difference" in the upcoming elections. Nearly 70 other countries, including Haiti, Colombia, and the Dominican Republic, already allow absentee voting.

But, even as supporters of the bill danced and waved flags outside Congress Tuesday, others were more circumspect, applauding the general sentiment but finding fault with the fine print, such as the decision to use the postal system in a country notorious for its slow and inefficient service; the ban on campaigning overseas, where Mexican expatriates are hungry for information; and the decision that only those already registered to vote would be eligible.

"Those voters better start sending in their preferences tomorrow," says Jaime Vazquez, busy arranging a package to ship to his family in Montana via, tellingly, a private courier. Mr. Vazquez says he has no confidence in the normal Mexican mail and has "no idea" what Congress is thinking by suggesting it play such a star role in the presidential election. "I don't even send Christmas cards by regular mail anymore," he says. "Because they would get there in March."

An earlier plan to set up ballot boxes at embassies and consulates was pronounced too complicated, and scrapped.

"I am upset because I want to see the politicians here talking to us," added Mújica from Chicago, referring to the section of the bill that prohibits campaigning or advertising outside of Mexico because of campaign-finance restrictions. This is, ironically, in stark contrast to previous years when candidates, including Fox himself, would stump in states like California, Texas, Illinois, Arizona, and Georgia, which have large Mexican communities, urging migrants to "call home" and influence the votes of their relatives back in Mexico. "They are asking us to vote blind," complains Mújica.

Most controversially, perhaps, the bill stipulates that only migrants who are already registered to vote in their districts in Mexico will be eligible to vote in 2006; there will not be a voter registration campaign. The IFEestimates that some 4 million migrants will be eligible under this condition.

But a March survey by the Pew Hispanic Research Center found 87 percent of the estimated 10 million Mexicans in the US would vote in the next Mexican election if given the opportunity - which could seriously affect the election. The entire Mexican electorate is estimated at about 65 million, and Fox won the last election with 16 million votes.

Despite the Pew findings, Gregory Rodriguez, a senior fellow at the New America Foundation, a Washington think tank, does not believe that many migrants will come out to vote, even if all were given the chance. "Those lobbying for this vote have typically been in the US for a long time and have the luxury of dabbling in politics for fun," he says. "But if you are an undocumented migrant, you are far more interested in survival and mobility within the US than homeland politics."

Who will benefit?

The most enthusiastic supporter of the bill over the years has been the left-leaning Democratic Revolution Party, headed by popular Mexico City Mayor Andrés Manuel López Obrador, who, his supporters claim, has most to gain by franchising the migrant vote. For years, conventional wisdom said that migrants, many of them driven from their homes to the US to look for better economic opportunities during the 71 years of rule by the Institutional Revolutionary Party, would vote "antiestablishment," and lean as left as possible. But today, experts say it is harder to make such assertions, and it is unclear whom the overseas vote might favor.

"Mexicans in the US are a mirror of Mexico, with all its different political leanings," says Jose Luis Guttierez, president of the Michoacan Federation, a political organization in Chicago, who lobbied for the passage of this bill. "It will depend on which candidate offers a better agenda for migrants. We listen, and we vote."

IFE's President Luis Carlos Ugalde told Congress that the system was not perfect, but argued it was "a good solution," and "technically and logistically viable for the elections in 2006."

"We have been working on this system for close to a decade," says Patricio Ballados, a senior adviser at the IFE. "We have all the plans mapped out. And now, with the passage of this bill we will go into overdrive to get it done."

• Ms. Harman is Latin America bureau chief for the Monitor and USA Today. Eloise Quintanilla contributed to this report.